The present invention relates to a switch means for short-stroke push-button keys which utilizes the snap-action effect of a profiled flat spring based on the snap-action principle. Two push-button key positions are provided in which a contact connecting piece is actuated from the bending point of a flat spring element, and either serves to bridge a pair of electrical conductors or other fixed contact points, or to remove the connection thereof.
In one conventional type of solution utilizing the snap-action principle, the flat spring element is designed as a thin-wall membrane which, when pressed, snaps into a position to make electrical connection with a fixed contact. One disadvantage of this arrangement resides in the fact that a metal is required which is suitable for use as a spring material and also as a contact material. Moreover, this arrangement only operates as a single-pole make contact, which restricts the range of practical applications.
Other conventional types of snap-action switches have the disadvantage that the switches and, more particularly the fixed contacts, are often arranged on the side of the printed circuit board not facing the circuit. It is therefore necessary to provide for plated through holes as well as for a printed circuit on both sides of the board.